THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

[18:00:02]

WOLF BLITZER, CNN ANCHOR: We want to welcome our viewers in the United States and around the world. I'm Wolf Blitzer. You're in THE SITUATION ROOM.

On this Labor Day, when the general election campaign heats up, a new twist in Donald Trump's still evolving immigration plan. Trump now says he's keeping his options open on whether to grant legal status to undocumented immigrants.

Just last week, Trump vowed there would be only one route to legal status, to go back home and reapply for entry to the United States.

In a new interview, Hillary Clinton says there's nothing new about Trump's immigration stance, insisting he's taking as hard a line as ever.

And, tonight, the Democratic nominee is answering questions from reporters flying with her on her plane. Stand by for that.

Also tonight, President Obama cancels an upcoming meeting with the president of the Philippines, this after the president, Rodrigo Duterte, lashed out at Mr. Obama, calling him -- and I'm quoting him now -- "a son of a whore," and saying he wouldn't be lectured on human rights by the U.S. president.

And we have exclusive new details about how the ISIS terrorist behind the Paris terror attacks traveled from Syria along the route taken by refugees. CNN obtaining thousands of pages of information from the investigation, including never-seen photos and texts between ISIS attackers and their handlers in Syria. Stand by for that.

I will talk presidential politics with Democratic Congressman Hakeem Jeffries. And our correspondents, analysts and guests, they will have full coverage of the day's top stories.

Up first, CNN senior White House correspondent Jim Acosta with more on Trump and his campaign swing through Ohio.

ACOSTA: Problem is, Trump has already scratched that idea in the past to CNN.

TRUMP: Is no path to legalization.

(CROSSTALK)

TRUMP: Unless people leave the country -- well, when they come back in, if they come back in, then they can start paying taxes. But there is no path to legalization, unless they leave the country and come back.

ACOSTA: Trump's visit to this county fair in Ohio was a clear sign that the finish line to this carnival of a campaign is on the horizon.

But this stop wasn't the only reminder that Labor Day is the traditional kickoff to the fall election season. There was also the image of Hillary Clinton's campaign plane parked in Cleveland within view of Trump Force One.

HILLARY RODHAM CLINTON (D), PRESIDENTIAL CANDIDATE: I am so happy to have all of you with me.

ACOSTA: And not to be outdone by Clinton's call to bring her traveling press aboard, Trump invited a small pool of reporters to join him on his plane as well to talk about the economy.

TRUMP: We want to bring back jobs.

ACOSTA: But as he reached out to blue-collar workers in Cleveland, Trump had his eye on one other plane.

TRUMP: They are having a fight on the tarmac.

ACOSTA: Trump pointed to that diplomatic dust-up in China from over the weekend, when Air Force One was not greeted with a staircase, forcing Obama to use a back exit as he arrived for a G20 Summit, proof, Trump said, that Mr. Obama gets no respect on the world stage.

TRUMP: They won't even give him stair,s proper stairs, to get out of the airplane. You see that? There are pictures of other leaders that are going there and they're coming down with a beautiful red carpet. And Obama's coming down a metal staircase. It is a sign of such disrespect.

ACOSTA: Trump then tied the president's trip to Clinton, predicting more unfair trade deals for Ohio.

TRUMP: It will be the equivalent of NAFTA. I'm not sure if anything can be as bad as NAFTA.

ACOSTA: The Trump campaign is continuing to hammer Clinton over that recently released FBI report on her use of a private e-mail server, pointing to investigators' findings of score of e-mails deleted.

Deputy campaign manager David Bossie said in statement, "The cover-up is always worse than the crime, and voters have a right to know if these records were illegally destroyed and what role Clinton's aides may have played."

GOV. MIKE PENCE (R-IN), VICE PRESIDENTIAL CANDIDATE: It's just more evidence that Hillary Clinton is the most dishonest candidate for president of the United States since Richard Nixon.

(END VIDEOTAPE)

ACOSTA: Now, Trump also said he will participate in all three presidential debates, which get started later on this month, unless there's some sort of natural disaster, he said, like a hurricane.

And, Wolf, he went onto hint that his debate prep will be just as unorthodox as his campaign. He plans on forgoing the tradition of sparring with a stand-in for his opponent, something that obviously presidential candidates have done throughout the years. Donald Trump, at this point, does not plan to debate prep with a sparring partner standing in for Hillary Clinton at this point -- Wolf.

[18:05:18]

BLITZER: Interesting. All right, Jim Acosta, thank you.

On the Democratic side, we have breaking news right now. Hillary Clinton is holding a rare question-and-answer question with reporters on board her plane. And she's warning that both Democrats and Republicans need to take the threat of Russian interference in the U.S. election very seriously.

Let's bring in our senior political correspondent, Brianna Keilar.

Brianna, what are we hearing from Hillary Clinton?

BRIANNA KEILAR, CNN SENIOR POLITICAL CORRESPONDENT: Well, Wolf, Hillary Clinton talking about several different issues, including the U.S. government's belief that Russian intelligence is behind the recent hacks into Democratic political groups.

We're actually turning that sound around right now to show you. We should also add that Hillary Clinton gaggled with reporters in two parts because of a coughing fit that's been plaguing her today.

(BEGIN VIDEOTAPE)

HILLARY RODHAM CLINTON (D), PRESIDENTIAL CANDIDATE: And I will come back and talk to you more formally, but I wanted to welcome you on to the plane.

KEILAR (voice-over): Hillary Clinton's last two months on the campaign trail will be finally be spent on a plane with a room for reporters.

CLINTON: I was just waiting for this moment.

KEILAR: After more than 16 months traveling separately from the press corps that follows her every move.

Clinton is targeting the key state of Ohio, appearing at a Labor Day festival with her running mate, Tim Kaine, in Cleveland.

CLINTON: We need to make sure we have an election that validates the kind of positive future that will make life better for the people of Ohio. And empty promises and racist attacks won't do that.

KEILAR: Clinton's remarks interrupted by a lengthy coughing fit. But she still managed to fit in this jab at Donald Trump.

CLINTON: Every time I think about Trump, I get allergic.

(LAUGHTER)

SEN. TIM KAINE (D-VA), VICE PRESIDENTIAL CANDIDATE: Joe Biden.

KEILAR: Kaine in Pittsburgh earlier in the day with a little help from Pennsylvania-born Joe Biden, as he accused Trump of being out of touch with the middle class.

JOSEPH BIDEN, VICE PRESIDENT OF THE UNITED STATES: Know that there are so many people like Trump who look at us like we're not their equal. I'm sick of it. I have had it up to here.

KEILAR: Clinton is consistently leading polls in Pennsylvania, but her campaign's still focusing on the Keystone state, seeing it as a must-win for Trump. This Labor Day, Clinton and her big-name surrogates are blanketing blue-collar strongholds, Bill Clinton at a parade in Detroit, Bernie Sanders in New Hampshire, where he crushed Clinton in the Democratic primary now urging liberal Democrats and his young supporters to choose his one-time adversary over Trump. SEN. BERNIE SANDERS (I), VERMONT: My dislike for Donald Trump is not

just that he is a pathological liar. It's a problem. It is not just that he changes his views virtually every day. The media tries to keep up with him, and it is very difficult. What he has chosen to do is make the cornerstone of his campaign bigotry.

KEILAR: But the simmering controversy over Clinton's e-mail practices while secretary of state has boiled over yet again, the FBI releasing notes from their interview with Clinton that showed she claimed 39 times she did not recall or did not remember key details about her use of a private server for official business.

Clinton getting some backup from her vice presidential pick.

KAINE: There were e-mails that contain classified information that had been improperly marked. So, when she received the e-mail, the material that was classified, which is supposed to be flagged and identified as classified, in many instances was improperly labeled.

(END VIDEOTAPE)

KEILAR: Now, Tim Kaine also defended Clinton for not having a press conference for more than 270 days. He said that leading up to November 8, Clinton will be very, very accessible to the press.

Today, Wolf, that manifested itself in this gaggle that she had on board her plane, where she addressed a number of issues, including the belief by the U.S. government that Russian intel is behind the hacking of Democratic political groups.

Here is what she said.

(BEGIN VIDEO CLIP)

CLINTON: I'm really concerned about the credible reports about Russian government interference in our elections.

The fact that our intelligence professionals are now studying this and taking it seriously raises some grave questions about potential Russian interference with our electoral process.

When Putin was asked about it, he could barely muster the energy to deny it. Many of you saw that. In fact, he went on to say it was a good thing.

(END VIDEO CLIP)

KEILAR: And, Wolf, she also addressed these coughing fits, two of which he had today and which supporters of Donald Trumps have pointed to as a problem with her health, something that is unfounded when you come to investigate that.

[18:10:05]

She said: "I'm not concerned about the conspiracy theories. There's so many of them, I have lost track of them. And so I pay no attention to them."

Of course, experts, Wolf, have said that both candidates should release more information about their health.

BLITZER: All right, Brianna, thank you very much.

We're getting more of Hillary Clinton's give and take with reporters aboard her campaign plane. It just fed in. She was asked, for example, about her knowledge about the way information was classified when she was secretary of state. Listen to this.

(BEGIN VIDEO CLIP)

CLINTON: I went into the State Department understanding classification. I had been on the Senate Armed Services Committee for years before I was secretary of state.

I take classification seriously. The fact I couldn't remember certain meetings, whether or not they had occurred, doesn't in any way affect the commitment that I had and still have to the treatment of classified material.

(END VIDEO CLIP)

BLITZER: Let's get the Democratic take on the presidential race now.

I spoke with Republican Congressman and Donald Trump supporter Sean Duffy in the last hour.

Joining us this hour, Democratic Congressman Hakeem Jeffries of New York. He's a member of the Congressional Black Caucus. He's also a strong Hillary Clinton supporter.

Congressman, thanks very much for joining us.

REP. HAKEEM JEFFRIES (D), NEW YORK: Thanks for having me, Wolf.

BLITZER: This latest statement we just heard from Hillary Clinton, aboard her plane, is that enough to reassure voters about her handling of classified information, which you know the FBI director said was extremely careless and negligent?

JEFFRIES: Well, Hillary Clinton has apologized, first and foremost, for the use of an e-mail server and indicated that if she had to do it all over again, she would take a different approach.

What we have seen, repeatedly, is attempts by Republicans to sort of continue to beat this issue like it's a pinata in order to distract from the fact that their presidential candidate has historically high disapproval ratings, particularly in communities of color all across the country.

Hillary Clinton, I think, will continue to answer questions directly and candidly about what took place during her time as secretary of state. This is another example of that fact, Wolf. And the American people, I think, overall will be assured that she has the discretion and the judgment necessary to be commander in chief and to handle classified information.

BLITZER: But, Congressman, you know that both of these candidates have high unfavorable ratings. A recent poll had Hillary Clinton at 59 percent, Donald Trump at 60 percent. They both have a lot of work to do. You care about Hillary Clinton. What does she need to do now to reduce that number?

JEFFRIES: Well, I think at the end of the day, she's been the victim of more than 30 years of a Republican relentless attack machine both during her time in Arkansas as the first lady to then Governor Bill Clinton and then of course Washington in the 1990s, then as a United States senator here in New York, and of course as a member of the Obama administration as a Cabinet secretary thereafter, and a two-time presidential candidate.

I think she just needs to continue to do what she has been doing, which is to address the problems confronting the American people, lay out a clear agenda and strategy for how to continue to build upon the progress of President Barack Obama as it relates to the economy, transportation and infrastructure, comprehensive immigration reform and, of course, our national security challenges.

And at the end of the day, a majority of Americans will be persuaded that she's the only candidate of the two main candidates for president who is ready, willing and able, has the capacity to step in on day one and be commander in chief.

BLITZER: She's doing this sort of gaggle, this Q&A with reporters aboard her new plane today, but a full formal news conference, she hasn't had one in, what, about 270 days, by our count.

Her reluctance to do that, to talk to the press in a sustained way, maybe answering questions for an hour or so, the perception is she's not transparent enough. Is that an accurate perception?

JEFFRIES: Not at all. She's done a series of one-on-one interviews over the last year-plus time that she's been a presidential candidate, including in the presence of myself and others when I have been on the campaign trail with Hillary Clinton. And she's been willing to answer questions that have been thrown at her by reporters.

I think the Labor Day period that we're in right now in terms of the presidential campaign marks the fact that we're no longer in a marathon as it relates to the campaign. This is a sprint. And as evidenced by the gaggle that she conducted today, she will comport herself accordingly in terms of access to reporters and continue to speak directly to the American people, which she has been doing during the duration in this campaign, Wolf.

BLITZER: She just promised the reporters aboard her plane that there would be significant changes to how the Clinton Foundation operates. What do you think? Does Bill Clinton, for example, need to step down if Hillary Clinton is elected president? [18:15:00]

JEFFRIES: Well, I'm confident that the Clintons, both Secretary Clinton, as well as President Bill Clinton, will do what is necessary in order to create confidence amongst the American people that there's adequate separation between the foundation and the Hillary Clinton administration once she's sworn in as president.

I think we're in a unique circumstance here, because you have a former president who a presidential candidate is married to. She served as first lady. Then she was a United States senator, then a secretary of state.

And, if anything, this speaks to the lifetime of service of both Clintons. And as a result, in terms of their continued work through the foundation, they're going to have to disentangle things in a way that would make the American people comfortable.

But, Wolf, let's be clear. This is all a result of the fact that they have both dedicated their life to trying to improve the condition of both the American people and people across the world, as they have done with respect to the Clinton Foundation, particularly on the issue of HIV and AIDS in Africa and other parts of the undeveloped or underdeveloped world.

BLITZER: I need you to stand by, Congressman. We have more questions.

We need to take a quick break. Let's do that. We will be right back.

(COMMERCIAL BREAK)

[18:20:31]

BLITZER: We're back with Democratic Congressman Hakeem Jeffries of New York.

Congressman, on this Labor Day, the unofficial start of the fall general election battle, we have another question about Hillary Clinton. She's facing a lack of enthusiasm, according to reports, especially among younger black voters. And today, Sean "Diddy" Combs criticized her for not speaking directly to the issues facing the African-American community.

Here's the question. Is she taking black voters for granted?

JEFFRIES: Not at all.

In fact, Hillary Clinton, as you recall, Wolf, began her campaign, the first major speech of this entire presidential journey was up in Harlem at Columbia University, where she spoke to the issue of the need to deal with mass incarceration in America, which has disproportionately impacted the African-American community -- 1971, when the war on drugs was -- began by Richard Nixon, less than 350,000 people were incarcerated in America. Hillary Clinton of course has pointed that right now we have got more

than 2.1 million, disproportionate number of those individuals African-American and Latinos. And she's laid out a clear strategy for how to deal with that issue. She's spoken to economic issues and other issues of importance to the African-American community.

So, I have got a lot of respect for Sean Combs as a hip-hop mogul, but in terms of policy, I think Hillary Clinton has been dead on in terms of dealing with the issues of importance to African-Americans.

BLITZER: And, Congressman, on another issue, a very important issue, President Obama today said during his visit to China he's yet to hear a persuasive argument against the Trans-Pacific Partnership, the TPP, from either the right or the left.

Is that a criticism of Hillary Clinton, who has lately been very critical of the TPP?

JEFFRIES: Well, Hillary Clinton and President Obama have agreed to disagree on this issue.

I'm supportive of Hillary Clinton's position. I voted against providing President Obama with fast-track authority last year. And I stand against TPP. I think we have got to deal with the fact that these trade agreements in the past have not by and large benefited the average American worker.

That's the position that Hillary Clinton holds right now as it relates to TPP. And I think she's correct. I understand that President Obama has a very different position. But much of his argument is anchored in the geopolitical strategic benefits that would be provided to the United States as it relates to defining the rules of trade in the Pacific Rim in particular.

Hillary Clinton is focused on dealing with the economic realities of the American people who have been hurt by trade agreements. And I'm entirely supportive of that position.

BLITZER: Congressman Jeffries, thanks very much for joining us.

JEFFRIES: Thank you very much, Wolf.

BLITZER: Just ahead: A world leader, a group of them show some stunning disrespect, at least one in particular calling the president of the United States -- and I'm quoting him now -- "a son of a whore."

Will Donald Trump use that against Hillary Clinton?

And CNN obtains secret texts between ISIS leaders and suspected terrorists who are supposed to carry out yet more terror attacks.

(COMMERCIAL BREAK)

[18:28:08]

BLITZER: The breaking news tonight, a rare move by Hillary Clinton. She's been answering questions from journalists who have been traveling with her.

Brianna, you have had a chance to go through this exchange that Hillary Clinton had aboard her new plane with reporters. Substantive questions were asked.

KEILAR: There were a number of questions.

Let's start with her e-mails. She addressed this. She was asked if she had a casual relationship towards classified information. She insisted she did not, that she takes it very seriously while she was secretary of state, while she worked in the Senate.

About this aide who had used something called BleachBit to erase some previously purged e-mails, but to fully erase them, she said: "I don't know about that. It's not something I'm aware of."

She also talked about Guantanamo Bay. She said closing it should be the goal of the next president. She talked about Russia. She said that obviously Vladimir Putin sees a benefit in disrupting what we have seen -- you have U.S. officials who believe that Russia has been behind these hackings of Democratic groups, political groups.

And she also talked about her health, because you have a lot of Republicans backing Donald Trump who are looking at these, the coughing that we saw she had twice today. And she said she's not concerned with conspiracy theories. We should add, there's nothing to back up that she has a health problem, although medical experts are saying that both of them should release information. She covered a lot of things.

DANA BASH, CNN SENIOR CONGRESSIONAL CORRESPONDENT: She did. She did, a lot of substance and a lot of substantive questions.

KEILAR: I know. I was running through a list there.

BASH: And, unfortunately, for her -- and I have been there -- I have been there on your show where I have had to get up because I'm coughing because I have a cold -- she had to stop her press conference.

KEILAR: Yes, her gaggle, her gaggle on the board the plane.

BASH: The second one for a couple of minutes to go get some water because of a coughing attack.

[18:30:02] KEILAR: She said it's pollen, and this happened to her last Labor Day. But she's dealing with a lot of Republicans who are bringing up these issues, and they're really unfounded.

BLITZER: She's been under a lot of pressure, Jackie, to do these kinds of Q&A with reporters. And today, she did it aboard her new plane.

KUCINICH: Well, hope -- let's hope that this is a habit now. Yes. With reporters traveling with you, it is a little -- a little bit harder to hide. You still can do it, but when they're walking by you every single day and you're there chatting questions, perhaps you'll get a little bit more comfortable with the press that are traveling with her. We sure hope so. Because that is a critical part of this process, is to address the press every day.

BASH: Can I just add, for all of us who have been on press planes or on candidates' planes in the press area in the back during campaigns, it's mutually beneficial. I fundamentally believe that it helps the candidates for the press to see them in their -- sort of in their comfort zones. Not that these are -- being on a plane with all these people is that comfortable. But to see them as people, not just on the stump or in their kind of prescribed areas is very helpful. It's very helpful for reporters, in how they craft their story, how they see the candidate. Don't you think?

I mean, you covered Bill Clinton. You saw him, probably, in the back of the plane more than any other president. But it's good for both of us.

BLITZER: It's good for the American public...

BASH: Exactly.

BLITZER: ... to have reporters be their surrogates and ask these candidates questions that are of interest to voters out there, because the voters need to know as much as possible who's going to be the next president of the United States.

And interestingly enough on this day that Hillary Clinton invited reporters on her plane, there's going to be a press pool on her plane, Donald Trump invited reporters on his plane, as well. He took a series of substantive questions.

At one point, he seemed to indicate, David, that he's maybe, a little bit, softening his position on whether or not undocumented immigrants can have a legal status here in the United States, even if they don't leave the country.

SWERDLICK: Yes. And I believe the phrase he used was that all things are on the table, which is different than what he said in his immigration speech last week, which was different than what he said the week before, which was different from what he was campaigning on for most of the primaries.

I think the Trump campaign is struggling right now to land in that sweet spot where they hold onto the sort of -- their core supporters who were really moved by this idea of building a wall, kicking undocumented immigrants out, and expanding their electorate to voters of color, to younger people, to what you would call upscale whites, educated, suburban, affluent folks in the suburbs who they need if they're going to challenge Clinton.

BLITZER: Because he did seem to indicate a new position today, at least compared to what he said last week and the week before.

KEILAR: Certainly. And that's really been one of his issues. Right? The Clinton campaign, as they see it, is they just want to hold him to what he started his campaign on, talking about Mexico not sending their best. Some of them being criminals and rapists. That he's talking about building a wall, that he's talking about a deportation force.

And I think they -- they feel that they can emphasize that in ads, which were seen going up in these battleground states, that are repeating these positions. And honestly, they're pretty hard positions to move away from. They're extremely memorable. They are the pillars of his campaign.

KUCINICH: But he's going to have to get an answer on this. There's a primetime presidential forum. It's not a debate but a forum this week. And then on the 26th, you have the first presidential debate. And you have to imagine that he's going to get questions about this and the variations that he's taken in his immigration plan in both of those forums, to nail it down. And that's when people are tuning in. This is when it counts.

BLITZER: It was interesting today, if you were watching, the president at his news conference that was here in the United States early this morning in China. He was asked to react to what the president of the Philippines said, who called him -- and I'm quoting him now -- "a son of a whore." A son of a whore.

This is the Filipino president speaking about the president of the United States. And the president of the United States later announced, you know, that meeting they were supposed to have between the U.S. and this U.S. ally...

BASH: Right.

BLITZER: ... not going to happen because of that.

BASH: Right. He cancelled the bilateral meeting. And why wouldn't he? Right? I mean, he did what you would expect a president of the United States to do if you're called something so vulgar by another world leader who you're supposed to meet with later in the day or the next day.

Look, Donald Trump is already using things like this. I haven heard him talk about this specifically, but the idea that there was a malfunction with the stairs when he arrived -- when the president arrived at the summit, and he had to go back down the back stairs, as proof that world leaders don't respect the president.

You could also look at the flip side as that maybe this is the Trump- ization of sort of global leadership that people can -- can just say -- just feel that they can say what they want to say, and -- and you know, maybe it's him feeling like he's politically correct, him meaning the head of the Philippines. But it also is certainly not the way we have come to expect world leaders to speak, especially about one another. [18:35:14] SWERDLICK: If voters -- and if voters want something more

like that, they're obviously going to have that option come November.

But I think it would be wise for the Trump campaign to reflect on the way that President Bush handled the shoe throwing incident at the -- right at the end of his term. That is in line with the way Obama is handling this incident. You know, when you're the world leader, when you're the leader of the free world, you have to take some of these incidents and deescalate them, rather than escalate.

BLITZER: And the president of the Philippines, President Duterte, he must apologize to the president of the United States. I think everyone can agree on that.

All right, guys. Stand by. Much more coming up.

Also, CNN's exclusive look at the trove of documents in the Paris terror ISIS attack. Disturbing new information about terrorists hiding among Syrian refugees.

(COMMERCIAL BREAK)

[18:40:25] BLITZER: Tonight, exclusive new details about the way ISIS plans and carries out terror attacks against western countries. CNN has obtained tens of thousands of pages of documents from the investigation into the Paris terror attack. They include photos that have never been shown to the public before and actual communications between the ISIS terrorists and their handlers.

CNN senior international correspondent Clarissa Ward is joining us now with her exclusive report.

Clarissa, you spent months working on this report.

CLARISSA WARD, CNN SENIOR INTERNATIONAL CORRESPONDENT: That's right. And it wasn't just me. It was a team from investigative unit. We had tens of thousands of pages of documents, most of them in French. We spent months poring over them, and in the process, we got an unprecedented window onto ISIS's inner machinations and how they orchestrate attacks in the west. Take a look.

(BEGIN VIDEOTAPE)

WARD: November 13, ten ISIS operatives attacked Paris, targeting bars, restaurants, a concert hall and a stadium, shooting as many people as they could before blowing themselves before blowing themselves up. By the end of the massacre, the worst terrorist attack in Europe in a decade, 130 people were dead.

Now, for the first time, CNN has gained access to thousands of pages of document and photos from the internal European investigation, which shed new light on the sophisticated network ISIS uses to coordinate terror attacks across Europe.

The documents reveal another suspected terrorist, never been made public, who investigators linked to the cell that carried out the Paris attacks. He was on the loose in Europe for more than six months. Other ISIS operatives are right now believed to be living among ordinary citizens in Europe, plotting other strikes directed by senior ISIS handlers in Syria, according to multiple sources.

Within days of the shocking rampage in Paris, police learned that two of the three suicide bombers at the Stade de France stadium entered Europe by posing as Syrian refugees. These surveillance photos, never seen before publicly, show the bombers as they approach their target. This is the moment they detonate their devices.

But according to the documents, two more men were part of the ISIS cell. They traveled the same refugee route as the suicide bombers, blending in with thousands of people from war-torn countries. Their names are Adel Haddad and Mohammad Usman. They were eventually arrested, and records of their capture and interrogation, obtained by CNN, show how ISIS supported the attackers throughout their mission.

his is their story, based mainly on multiple interrogations. Early October, six weeks before the Paris attacks. The documents show their journey began in Raqqah, Syria, the capital of the self-declared ISIS caliphate.

The men didn't know each other's real names or what their mission would be. According to the documents, Haddadi later tells investigators he only knew they were being sent to France to do something for the good of God.

Much of their journey was directed by a shadowy ISIS leader in Syria known only as Abu Ahmad, who arranged meetings, cell phones, money and transportation for them.

Jean-Charles Brisard is a French expert on terrorism. We asked him to analyze the documents obtained by CNN.

JEAN-CHARLES BRISARD, EXPERT ON TERRORISM: Abu Ahmad is clearly An ISIS operative. He is key in sending those individuals, the foreigners, into the Paris attacks, because he's the one who recruited them, who funds them, who trained them, who provided electronic devices to them, telephones. He was always in contact with them.

WARD: According to the transcripts of interrogations, Haddadi and Usman, along with the two Paris attackers, traveled from Raqqah across the Turkish border onto the coastal city of Izmir, switching vehicles, picking up cash, passed from one smuggler to the next along the way. They receive instructions from their ISIS handler in Syria through encrypted apps such as Telegram and What's App. Throughout their journey they're only given enough money and information to get to the next stop.

PAUL CRUICKSHANK, CNN TERRORISM ANALYST: ISIS is accelerating its international attack planning. It's increasingly sophisticated in the way it does this. It's set up an intricate logistical support system for these terror cells throughout Europe.

[18:45:00] WARD (voice-over): In the middle of the night the team makes the treacherous crossing to Greece in a boat filled with dozens of refugees. They picked up by the Greek Navy along the way.

The two bombers who would eventually attack the Paris stadium make it through and start moving steadily north toward their target.

But Haddadi and Usman's fake Syrian passports are discovered. They're arrested and their money is taken. They're held in Greece for about a month. Greek officials would not say why they were released, but authorities believe that delay was significant. They would not have a chance to become part of the Paris attacks.

Haddadi tells investigators they contact their ISIS handler, Abu Ahmed, who arranges another 2,000 euros for them. Flush with cash, the pair continue along the refugee route. As they work their way across Europe, Usman, identified by investigators as a bomb maker from a Pakistani terror group, passes the hours doing something strikingly un-Islamic, looking at porn. Documents show he visited almost two dozen porn sites on his phones.

November 14th, the day after the Paris attacks, Haddadi and Usman arrive in Salzburg, Austria. They apply for asylum and end up in this refugee center, where they stay for weeks.

(on camera): According to CNN sources, authorities now believe that Haddadi and Usman were not only part of the same terror cell as the Paris bombers, but also that they were planning another attack. The documents show that they were in contact with people in several European countries and were researching travel to France.

(voice-over): Investigators believe they were waiting for a third man to join them, a mysterious ISIS operative called Abid Tabaouni. Tabaouni has never been publicly named until now. Like Usman and Haddadi, he traveled from Syria along the refugee route, carrying a phone number linked to the terror cell of the ring leader of the Paris attacks, according to the documents, as well as a photo of Islamic State fighters standing before their flag.

December 10th, nearly a month after the Paris attacks, Tabaouni finally arrives at the refugee center where Usman and Haddadi are. Later, the very same day, police raid the center. Usman and Haddadi are arrested.

Here's what happened next according to the documents. In the scramble, Haddadi tries successfully to get rid of his SIM card. Tabaouni is nowhere to be seen. Haddadi denies knowing him, but investigators find this, Tabaouni's cell phone charging right beside Haddadi's bed. It has Haddadi's phone number saved in it.

Also in that phone, a photo taken just 30 minutes before the raid that shows Tabaouni sitting on a bed in the refugee center right next to where Haddadi and Usman slept.

JEAN-CHARLES BRISARD, FRENCH CENTER FOR ANALYSIS OF TERRORISM: We can assume that Tabaouni was also part of the same plot and was instructed to carry out an attack.

WARD: From the time he slipped away last December, Tabaouni has been a wanted man, according to CNN sources, who also confirm he was finally arrested in July. The documents show this is the Facebook page Tabaouni had on his phone. And in recent months, it appears he was publicly posting updates from Belgium.

Investigators are now analyzing 1,600 pages of data from his phone, and sources tell CNN they are moving to extradite him to Austria and to tie him to Haddadi and Usman and the Paris attackers.

(on camera): Are you concerned that there may be many others who use the same route who we just -- who you just didn't know about?

BRISARD: Yes, we've seen that in the recent weeks. Several of them, individuals who carry out individual attacks, inspired attacks, were coming back from -- from Syria using this same route.

WARD: So there's a possibility that there are many more that you just don't know about?

BRISARD: There is a high possibility.

WARD (voice-over): The documents show Haddadi's phone has also proven to be a treasure trove for investigators, revealing an ISIS network that fanned out through southern and northern Europe. He had dozens of contacts. Some gave advice on crossing borders and evading the law. One tells Haddadi that he was able to sneak into France by hiding in the bathroom of a train.

December 15th, five days after the raid, ISIS handler Abu Ahmed reaches out to his operatives, Haddadi and Usman, perhaps wondering about their silence. "How are you?," he writes. "What's become of you?" There is no reply.

(END VIDEOTAPE)

WARD: Now, Wolf, we do have some updates on Haddadi and Usman. According to CNN sources, they have been extradited to France and since our story came out this morning, we're now hearing that Austrian media, citing prosecutors, is saying that the third ISIS operative suspect Abid Tabaouni has been extradited to Austria from Belgium, where he was arrested.

[18:50:04] But Belgium sources have told me, Wolf, that they believe there's as many as 30 to 40 people who were involved with facilitating the Paris attacks who are still at large, Wolf.

WOLF BLITZER, CNN ANCHOR: Wow.

All right. Clarissa, I need you to stand by. We have much more to discuss about this exclusive report on ISIS, what the documents obtained by CNN reveal about the threat to an attack here in United States.

That's right after a quick break.

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[18:56:08] BLITZER: We are back with CNN senior international correspondent Clarissa Ward and her exclusive reporting on the way ISIS plans terror attacks against the West.

Our CNN terrorism analyst Paul Cruickshank is joining us as well. He worked very closely with Clarissa on this investigation.

Clarissa, what do these documents reveal about how ISIS plots attacks?

WARD: Well, I think one of the things that really struck us as we were going through these documents, it's easy to under estimate ISIS given all of the rhetoric that we hear out there about them. But in actual fact, they do appear, especially in this instance, to be running a pretty sophisticated operation.

What was interesting was the way in which the operatives described never knowing in advance exactly what the end goal was. They were only given instructions one step at a time. They were only given enough money and enough information to get to the next step in their journey.

And what seems clear as well, when you look at the broader picture of this network they built up is that many people in the network don't even know they are in fact directly part of a network that is plotting a terrorist. People are only given as much information as they need to complete their very specific task. And that means that as the ISIS handlers back in Syria, the man known so-called Abut Ahmed in our report, who, in fact, the very few people who have a full view of the entire operation as it's unfolding on the ground, Wolf.

BLITZER: Paul, investigators believe ISIS was initially planning an even more ambitious attack than the one we saw in Paris last November. What are you learning about this?

PAUL CRUICKSHANK, CNN TERRORISM ANALYST: Wolf, I see European counterterrorism officials telling me that according to interrogations, according to intelligence, now indications that they were planning a much bigger more ambitious plot than the Paris attacks. They were forced to scale that back when some of the operatives were not able to reach their destination.

The intelligence suggesting those targets were going to be in the Netherlands and also in France notably shopping centers, supermarkets in Paris. So, this could have been much worse than it was.

BLITZER: Clarissa, what does this investigation reveal about the possibility of your sleeper cells throughout Europe and even here in the United States?

WARD: Well, this is what's quite chilling about looking through these documents, Wolf, because you realize these were three operatives, and yet, they were clearly in touch with so many different people, fanning out all across of Europe and various other countries as well.

And what you realize is that it's very difficult for investigators to know who might be involved in something dangerous and who is just an innocent contact. Let me give you an example. Haddadi was in contact regularly on his phone with a man in France who was a researcher at a top nuclear -- a technician rather at a top nuclear facility. This obviously would send a lot of red flags up. And we know that French authorities, according to the documents, upon hearing about the contact that this man was having with Haddadi, immediately placed him under observation.

But it's difficult. How can investigators know concretely that there was anything pernicious in terms of this contact?

We also know of two another men who were arrested in that refugee center, along with Haddadi and Usman. And throughout the documents, there are many, many instances of peoples whose names will pop up once or try and investigators clearly trying to seep through all the data, go through all the phones and find out who is a threat and who is just an innocent bystander.

BLITZER: Clarissa Ward, thank you so much for your excellent reporting.

Paul Cruickshank, thanks to you as well for participating for all of this.